Observation of Morphology and Proliferative Density for Cashmere Goat Fetal Fibroblasts after mTOR Inhibition with Optical Microscope Cell Imaging

The mammalian target of rapamycin (mTOR) is a kind of Ser/Thr kinase in mammalian cells. It can recruit and integrate input signals from modulators such as nutrients and growth factors to regulate cell growth and proliferation via different cellular processes. The mTOR signaling pathway also affects the development of the embryonic stem cells (ESCs) and early embryo, and involved in cancers and metabolism disease. The mTOR signaling pathway has been investigated extensively in human, mouse and rat, whereas it is not yet studied in goat due to the lack of basic data about genes, gene expression and function. Thus this study uses the CCI-779, an mTOR specific inhibitor, treating Inner Mongolia Cashmere goat fetal fibroblasts (GFb) to prove that the mTOR signaling pathway acts as regulator in the cell proliferation. The GFb cells were treated with different concentrations of CCI-779 (0.1 μM, 1.0 μM, 5.0 μM, 10.0 μM and 20.0 μM) for 24h and 48h, and then the cell shape and proliferative density were observed with optical microscopy cell imaging. The results showed that GFb cells were sensitive to CCI-779. CCI-779 inhibits the cell proliferation. Dead Cells floating on medium were clearly observed after 10 μM and 20 μM CCI-779 treatments for 24h. Some cells' shape changed to round from typical shape after treatment with 20μM CCI-779 for 48h. The Morphological results indicated that mTOR is functional in GFb cells and acts as a key kinase to regulate cell proliferation. The synthesis of microfilament or organization of cytoskeleton perhaps was disrupted in GFb cells when mTOR was inhibited. Taken together, the data showed that the mTOR signaling pathway plays a critical role in the GFb cell proliferation.